This invention relates to a method and device for throughly testing the braking system of a vehicle so as to identify any deficiency in performance of the brake system and also identify the cause of such deficiency so that such deficiency may be repaired and the cause eliminated.
Heretofore, brakes were customarily tested in a shop on a roller/torque device wherein the vehicle's wheels were placed on a pair of rollers driven by a torque motor that drives the wheels at a constant speed. While the wheels are turning, the vehicle brakes are applied and the magnitude of the torque drive required to rotate the rollers is then measured. Such measurement gives a measurement of the vehicle's brake force and thus an indication of brake performance. Such tests were often augmented, especially if brake performance was low, by a visual inspection of the vehicle's brakes which involves removal of the wheel and visual examination of the brake parts.
The prior methods were highly subjective and the results varied as to whether operation was within normal limits based upon the mechanic's interpretation of the appearance. The variety of results were primarily due to the failure of the test as most methods of brake testing are less than a scientific diagnosis of brake related problems. The methods that are now common practice in the automotive repair aftermarket are far from complete or accurate.
To properly inspect a brake system on today's vehicles, technicians must follow a flow chart, or a specific step by step procedure to determine the exact condition of each components in the brake system. Because most technicians do a quick manual inspection of the vehicle's brake system and then make an educated guess as to the condition of each of the brake components, the current state of the art often gives an inacurrate result.
Normal testing methods also fail to address a crucial issue in brake performance, i.e. the integrity of the brake hydraulic condition. Brake line fluid absorbs water quite readily and any opening in an otherwise closed brake system provides an area where water may be taken up by the brake fluid. When water is found in the brake fluid it promotes corrosion of the parts of the system which will produce a failure of the system at that corroded part.
Additionally the prior methods of brake testing do not relate the state of the brakes or their performance to optimal vehicle specifications as established by the manufacturer.